Sir Ian McKellen and Andy Serkis have signed up to reprise their Lord of the Rings roles in The Hobbit, it has been revealed.

According to The Hollywood Reporter, McKellen has finally agreed to return as Gandalf for Peter Jackson's upcoming two-parter, while Deadline has also confirmed that Serkis will appear once more as Gollum.

Both characters feature in the original J.R.R. Tolkien novel - although Gandalf's role stretches across the book, whereas Gollum's involvement is confined to one chapter.